Accurate functional assessment of a user's abilities is a key component of successful computer access interventions. Development of an easy-to- use software tool is proposed for measuring user's skills in various kinds of computer interaction, including motor actions, perceptual activities, and cognitive activities- This tool will help practitioners diagnose difficulties with an existing interface, evaluate and compare the expected performance with candidate access systems, plan training interventions, track changes in an individual's abilities over time, and measure the overall effectiveness of an intervention. The initial focus is on the motor actions necessary for computer use, with gradual expansion to incorporate assessments of perceptual and cognitive activities as well. In Phase I, a prototype specifically focused on the skill families of keyboarding and mouse/pointer use will be developed and evaluated in one clinical and one educational setting. Phase Il will expand the system to incorporate other skill families, such as visual perception of the computer display, to provide a comprehensive and integrated package. PROPOSED COMMERCIAL APPLICATION: The primary commercial application for the software is use by practitioners in schools, universities, worksites, and assistive technology clinics to enhance the quality of computer access assessments. Secondarily, researchers studying user performance with computer-based systems would also find this to be a valuable tool. In the long term, it is expected to provide a foundation for future development work in model simulations, adaptive interfaces, and interactive tutorial systems.